Even without cubs, Memphis Zoo expects to keep pandas Ya Ya and Le Le

October 18, 2012 — Le Le the panda, chews on some bamboo at his exhibit at the Memphis Zoo. As Le Le and Ya Ya's lease expires next year, rumors circulated if the zoo would exchange Ya Ya for a more fertile female due to several failed attempts to impregnated her. Memphis is one of four U.S. zoos with pandas and the only zoo to have never produced a panda cub. (Kyle Kurlick/Special to The Commercial Appeal)

FILE January 5, 2011 — Ya Ya, the Memphis Zoo's female giant panda, munches on a frozen fruit juice filled bamboo stick. In the past Ya Ya has gone into estrus around the holidays, but this year she did not which zoo officials say is a good thing. (Mike Brown/The Commercial Appeal)

Throughout the spring, the summer and into the fall, officials at the Memphis Zoo paced the waiting room, hopeful that Ya Ya, the female giant panda, would have a successful pregnancy and give birth to a healthy cub.

She did not, leaving the Memphis Zoo with that unfortunate tag line at the end of news stories about panda births, naming ceremonies or other milestones for cubs born in U.S. zoos in Atlanta, San Diego and Washington, D.C.

Memphis is the only zoo in the nation with pandas that have not produced a cub.

Ya Ya had her fourth insemination over a five-year period in March, but the pregnancy did not thrive.

"It bothers us, but I can't say it's not for lack of trying," said Chuck Brady, zoo president and CEO. "We had four pregnancies, none of them went to term. They were pregnancies that stopped at an early stage of development. After the animal got pregnant there was never any growth and development of the embryo."

Ya Ya and her male companion, Le Le, came to Memphis in 2003 as part of a 10-year breeding loan through the Chinese Association of Zoological Gardens, at a cost of $1.2 million annually.

The zoo intends to keep them and has recently offered to sign a second 10-year lease on the pandas at an annual rate of $550,000, Brady said.

"It's in the Chinese's hands right now," Brady said. "We're hopefully going to have it signed by the end of the year. There's a lot of politics going on in China right now and that's probably holding up the signing of this agreement."

The work that brought the pair to Memphis began in the late 1990s and was a five-year effort, aided by former Tennessee Senator Jim Sasser, then U.S. ambassador to China.

At the time, the Memphis Zoo had just undergone extensive renovations and modernizations.

In hopes of winning the coveted pandas, it modified its master plan, adding the $15.5 million China exhibit where the giant pandas and other animals native to the region are housed.

So, while Ya Ya and Le Le's future in Memphis may be all but secure, zoo officials can't say if they'll continue to try for a cub.

Because the zoo has the staff and the equipment to collect a sample from Le Le, inseminate Ya Ya and monitor her progress with regular ultrasound tests, the cost in dollars is no more than $6,000 an attempt, Brady said.

It's also hard on the people who work with the pandas and follow cub births at other U.S. zoos and in China, Thompson said.

"It's tough on the staff for sure, but we've got an excellent staff that has been through it before, so there's always guarded optimism with Ya Ya," he said.

But most importantly, insemination attempts are hard on the animals, especially Ya Ya, who must be immobilized for the insemination and other tests, Brady said. While the pandas are healthy, there are risks in the process of anesthetizing them, he said.

Ya Ya and Le Le are owned by zoos in China, which may opposetrying insemination again.

Ya Ya had her 12th birthday in August and panda females are fertile until about 20, but panda reproduction isn't easy.

"You can't just put them together and expect them to mate," said Dr. Ron Swaisgood, director of applied animal ecology at the San Diego Zoo, where six panda cubs have been born. (Most were fathered naturally by a wild-caught bear.)

To start, the female is only fertile for 1-3 days a year, Swaisgood said.

Once a female panda is inseminated, either naturally or artificially, there is a period of delayed implantation, meaning the embryo floats from three or four months. The total gestation period can be from 95 to 165 days, producing a cub that can weigh as little as one-fourth of a pound, compared to its 300-pound mother.

Even without a cub, the Memphis team has contributed greatly to the catalog of panda knowledge.

"To take the long view, before the panda program started in the U.S., we really knew very little about the panda," Swaisgood said. "One of the things that made the panda so popular was its mystery, but biologically, mystery is not a good thing."

Through the collective efforts of the four U.S. zoos with pandas and colleagues in China, books and scientific papers have been written about the animals and they are one of the better understood species, he said. Now dozens of panda cubs are born each year around the world.

"I'm friends with the people running the program in Memphis and as I'm following this, my heart goes out to them," Swaisgood said. "But it is important to realize, what happened to these pandas this year, it doesn't mean overall we're not doing pretty well and Memphis has made contributions to that."

Last month the Memphis Zoo was awarded top honors in the 2012 Association of Zoos and Aquariums International Conservation Award for its giant panda conservation and habitat program, an award shared with the zoos in San Diego, Atlanta and Washington."We've had a wonderful loan with the pandas. They've done a tremendous amount of good for our zoo and our community," Brady said. "Obviously, we'd like to have a cub or several cubs over time, but I don't think our panda loan has been anything but a great success."